Cancers, including leukemia, are the leading cause of death in humans. Roughly 32,000 new cases of, and 22,000 deaths caused by, leukemia occur in the U.S. each year. Most cases occur of leukemia occur in adults. The exact cause of leukemia is not known, but links between certain activities, such as exposure to carcinogens, and the incidence of certain types of carcinomas, lymphomas, e.g., leukemia and tumors, has been shown by a number of researchers. However, such exposures do not explain most cases of leukemia.
Acute myeloid leukemia (AML) is the most common type of acute leukemia in adults, with an annual incidence of 2.7 per 100,000 adults in the U.S. (Murashige et al., 2002). Progress in therapy and supportive care over the past three decades has led to a gradual improvement in the overall results; however, very little progress has been made regarding long-term survival. Newly diagnosed AML patients achieve complete remission (CR) following chemotherapy/radiation treatment, with a median duration of 15 months. A small percentage of patients with relapsed or refractory AML can be induced with chemotherapy/radiation to achieve a second CR and the duration of these responses are often only 4-8 months. Allogeneic stem cell transplantation (AlloSCT) has been conducted as a salvage therapy for those in whom conventional chemotherapy failed to control their disease, but most of them are relapsed.
Many types of chemotherapeutic agents have been shown to be effective against leukemia, but not all types of leukemia cells respond to these agents, and, unfortunately, many of these agents also destroy normal cells. Despite advances in the field of leukemia treatments, the leading therapies to date are radiation, chemotherapy and bone marrow transplants. However, these therapies generally harm normal cells as well as leukemic cells. Ideally cytotoxic agents that have specificity for leukemia cells while only minimally affecting normal healthy cells would be extremely desirable. Unfortunately, none have been found and instead agents which target especially rapidly dividing cells (both diseased and normal) have been used.
Thus there continues to be a strong need for methods of diagnosing and viable treatment regimens for leukemia.